How Many Alerts Does the N.W.S. Issue?

How Many Alerts Does the N.W.S. Issue?

NOAA: National Oceanigraphic & Atmospheric Administration of the United States Department of Commerce

It seems the number of alerts the National Weather Service issues is endless but the fact is they only issue (generally) 36.

Sometimes it seems the National Weather Service (NWS) has an endless number of alerts they issue and they can get redundant.

We have all experienced seasons where it seems like everyday the NWS issues a Fire Weather Watch. Or other days it seems like the lightest breeze results in a High Wind Warning or a Wind Advisory.

So how many alerts does the NWS issue and what do they all mean?

I thought I would take this time to answer the question. It is one of the most common questions I get when I am out and about, especially when something is issued over and over and over.

The answer is that the NWS issues 36 different weather alerts or at least has access to issue 36 different ones if it is needed in Texoma.

One recent example is the Heat Advisory that was issued and re-issued many times for six days.

Each office in the National Weather Service has different criteria for issuing alerts and the following list is based on the alert guidelines used at the Norman National Weather Service Forecast Office in Norma, Oklahoma. They have jurisdiction over a majority of our KFDX area including Wichita Falls and Lawton.

Here is a list of all the weather alerts used by the NWS Norman Office and the criteria they use to issue them:

Winter Season Watches, Warnings and Advisories

Snow AdvisoryIssued when accumulating snow of 2 to 4 inches is expected. An advisory may still be warranted if lesser accumulations will produce travel difficulties, especially early in the winter season.

Blowing Snow AdvisoryIssued when blowing snow is expected to occasionally reduce visibilities to 1/4 mile or less with winds generally 25 to 34 mph. The event should last at least 3 hours.

Snow and Blowing Snow AdvisoryIssued when winds of 25 to 34 mph are expected to be accompanied by falling snow and blowing snow, occasionally reducing the visibility to 1/4 mile or less. The event should last at least 3 hours.

Freezing Rain/Drizzle AdvisoryIssued for freezing rain when ice accumulations are expected to cause travel problems, but not exceed 1/4".

Sleet AdvisoryIssued for accumulating sleet of 1/4" to 1". Because sleet usually occurs with other precipitation types, a winter weather advisory will almost always be used in such cases.

Winter Weather AdvisoryIssued for a winter weather event in which there is more than one hazard present, but all precipitation is expected to remain below warning criteria. For example, it would be issued if 2 inches of snow were expected with a small amount of sleet mixing in at times.

Wind Chill AdvisoryIssued when wind chill values will reach -5°F to -19°F, with wind speeds around 10 mph or more.

Wind Chill WarningIssued when wind chill values will reach -20°F or colder, with wind speeds around 10 mph or more. A Wind Chill Watch is issued when these conditions may be met 12 to 48 hours in the future.

Ice Storm WarningIssued when a period of freezing rain is expected to produce ice accumulations of 1/4" or greater, or cause significant disruptions to travel or utilities.

Heavy Sleet WarningIssued when a period of sleet is expected to produce ice accumulations of 1" or greater, or cause significant disruptions to travel or utilities.

Heavy Snow WarningIssued when snow is expected to accumulate 4 inches or more in 12 hours, or 6 inches or more in 24 hours.

Winter Storm WarningIssued for a winter weather event in which there is more than one hazard present, and one of the warning criteria listed above is expected to be met. For example, it would be issued if 5 inches of snow were expected in 12 hours, with some sleet mixing in at times. It is commonly issued for heavy snow with strong winds of 25-34 mph that will cause blowing and drifting of the snow. A Winter Storm Watch is issued when these conditions may be met 12 to 48 hours in the future.

Blizzard WarningIssued for sustained wind or frequent gusts greater than or equal to 35 mph accompanied by falling and/or blowing snow, frequently reducing visibility to less than 1/4 mile for three hours or more. A Blizzard Watch is issued when these conditions may be met 12 to 48 hours in the future.

Severe Weather Watches, Warnings and Advisories

Severe Thunderstorm WarningIssued when there is evidence based on radar or a reliable spotter report that a thunderstorm is producing, or about to produce, wind gusts of 58 mph or greater, structural wind damage, and/or hail 1 inch in diameter or greater.

Severe Thunderstorm WatchIs issued by the Storm Prediction Center when conditions are favorable for the development of severe thunderstorms over a larger-scale region. Tornadoes are not expected in such situations, but isolated tornado development cannot be ruled out.

Tornado WarningIssued when there is evidence based on radar or a reliable spotter report that a tornado is imminent or occurring.

Tornado WatchIs issued by the Storm Prediction Center when conditions are favorable for the development of severe thunderstorms and tornadoes over a larger-scale region.

Significant Weather AdvisoryIssued for strong thunderstorms that are below severe levels, but still may have some adverse impacts. Usually issued for the threat of wind gusts of 40-58 mph or hail up to 1 inch in diameter.

Flooding Watches, Warnings and Advisories

Flash Flood WatchIssued generally when there is the possibility of flash flooding or urban flooding over an area within the next 36 hours.

Flash Flood WarningIssued when flash flooding is imminent, generally within the next 1 to 3 hours. Usually issued based on observed heavy rainfall (measured or radar estimated), but may also be issued for significant dam breaks that have occurred or are imminent.

Flood WatchIssued when there is the possibility of widespread general flooding over an area within the next 36 hours.

Flood Warning for River Forecast PointIssued when a river gauge has exceeded, or is forecast to exceed, a predetermined flood stage.

Flood AdvisoryIssued when flooding is imminent or occurring, generally within the next 1 to 3 hours, but is not expected to substantially threaten life and property.

Non-Precipitation Watches, Warnings and Advisories

Wind AdvisoryIssued when sustained winds of 30 to 39 mph are expected for 1 hour or longer.

High Wind WarningIssued when sustained winds of 40 mph or more are expected for 1 hour or longer, or for wind gusts of 58 mph or more with no time limit. A High Wind Watch is issued when these conditions may be met 12 to 48 hours in the future.

Dense Fog AdvisoryIssued when fog is expected to reduce visibilities to 1/4 mile or less.

Heat AdvisoryIssued when maximum daytime heat index values are expected to reach or exceed 105°F on at least 2 consecutive days, with intermediate low temperatures of 75°F or higher.

Excessive Heat WarningIssued when maximum daytime heat index values are expected to reach or exceed 110°F on at least two consecutive days, with intermediate low temperatures of 75°F or higher. An Excessive Heat Watch is issued when these conditions may be met 12 to 48 hours in the future.

Frost AdvisoryIssued when nighttime minimum temperatures are expected to range from 33°F to 36°F in the growing season.

Freeze WarningIssued when nighttime minimum temperatures are expected to reach 32°F or lower in the growing season. They are usually issued to highlight the first few freezes of the fall, or unusually late freezes in the spring. A Freeze Watch is issued when these conditions may be met 12 to 48 hours in the future.

Air Stagnation AdvisoryIssued only at the request of the Environmental Protection Agency (EPA), whenever atmospheric conditions are stable enough to cause air pollutants to accumulate in a given area.

Blowing Dust AdvisoryIssued when blowing dust is expected to reduce visibility to between 1/4 and 1 mile, generally with winds of 25 mph or greater.

Dust Storm WarningIssued when blowing dust is expected to reduce visibility frequently to 1/4 mile or less, generally with winds of 25 mph or more.

Dense Smoke AdvisoryIssued when smoke is expected to reduce visibility to 1/4 mile or less.